Cain and Abel
Cain and Abel, sons of Adam and Eve, brought offerings to the LORD. Abel, who was a keeper of sheep, brought a burnt offering from the firstlings of his flock; while Cain, a tiller of the ground, offered fruit. When Abel’s sacrifice was found acceptable and Cain’s was rejected, Cain was very wroth. And the LORD said unto him, “Why art thou wroth.... If thou doest well, shalt thou not be accepted? and if thou doest not well, sin lieth at the door.” Cain then slew his brother.
According to the rabbinical tradition recorded in the Zohar, the motivation for the murder was that "Cain was jealous of the twin sister that was born with Abel.”
After Cain killed his brother Abel, God gave to Adam and Eve another son, Seth, whose name is interpreted “consolation.” “He shall be the blessed seed, and the head of patriarchs, and shall be a comfort unto thee.” “And to Seth, to him also there was born a son; and he called his name Enos: then began men to call upon the name of the LORD.”
The ascended masters teach that the relative good and evil of the Cain/Abel consciousness must be transcended through the Christ typified in Seth, the Son of promise. It is through the person of Christ that men begin to call upon the name of the LORD, I AM THAT I AM. Only from that point of the Real Self can the true path of attainment be entered and won.
For more information
Mark L. Prophet and Elizabeth Clare Prophet, The Path of Self-Transformation.
Elizabeth Clare Prophet, The Opening of the Seventh Seal: Sanat Kumara on the Path of the Ruby Ray, chapter 37.
Pearls of Wisdom, vol. 25, no. 25, June 13, 1982.